check engine / running rough

[jamies98lsc]

if its not firing check the wire going to the number 8 coil pack for breaks in the wiring, see if there is something obvious, did you remove the plug from number 8? or is there no spark coming out of the number 8 coil itself? if the coil isnt firing then you have a broken wire(s) somewhere.

 

[BlackMark8]

i removed the plug, plugged in the new coil pack, and put the plug in the coil pack just to see if it sparks, and nothing. So i got a plug from a lawnmower to see if the coil pack will spark the plug i know is good and... shizam ! it sparked. So i am getting the new plug now and putting it in, hopefully this does the trick, thanks again everyone ! and ill let you know if i blew it up or not

 

[XLRVIII]

Yes bone stock, No tune, no other mods. What causes the check engline light to flash on and off, anyone know? oh and she has 160k miles

as posted before... check the plugs.

on an 97 a check engine light could be due to a missfire.
Since you say the car is running rough, that ALSO could be a missfire.

I also have seen Nitrous destroy spark plugs, all it takes is a "hint" of detonation, that you wont even HEAR...the tremendous cylinder pressures will either.. "close the plug gap" or break the electrode off.. or do all kinds of horrible things to your engine.

First step... Check the physical condition of the plugs.. and or gaps.

Second step.. "compression test", you may have blown a ring land off the piston {whish is also common on "non tuned nitrous cars".

Consider yourself lucky if your running a stock tune with nitrous.
There is FAR too much timing in the spark table.. for nitrous.. IMHO.

 

[XLRVIII]

guess I shoulda read page 3 before replying..

+1 for post count!

 

[J]

hat is the general cause of making the check engine light FLASH on and off??

What causes the check engline light to flash on and off, anyone know?

I thought someone here would know what the flashing check engine light means.

People on here DO know...but you've just been firing all sorts of questions man! A FLASHING check engine light means you have a constant MIS-FIRE.

Think the faulty O2 sensors can make it run crappy and make number 8 miss ??

No...a faulty O2 sensors CAN NOT make one cylinder mis-fire.

could the 02 sensors make it run rough and miss on number 8 ??

NO.

ok i changed my coil pack and boot, and still... not firing on number 8 cylinder, can faulty O2 sensors do that??

NOOOO.

Blue smoke is burning oil...

+1 for blue smoke....thats NOT good. White smoke is COOLANT, BLACK smoke is unburned fuel, NOT blue smoke.

it may have a valve guide leak and if piston is not firing then it builds up

Sounds like your uncle doesn't know what he's talking about. A valve guide seal leaking will usually show signs of leaking on start up, or after idling at a stop light. You will not see it blowing smoke while accelerating unless the actual valve guide is damaged or the seal is blown out.

im getting a spark plug now to test it on a new/different one.

You really should be saving your money by swapping parts like Jamie suggested rather than "throwing" parts at your car in a feutal attempt to fixing it.

Its probably too late, but if you want to check your mis-fire, swap the #8 cylinder coil pack/boot and spark plug to the #7 cylinder and start the car. Obviously its still going to miss but now you check to see if the miss moved to the #7 cylinder. You can do this by unplugging the electrical connector on the #8 coil pack while its running. If the car runs worse, you now know the miss moved to the #7 cylinder. If the car does NOT run worse, then you know the coil pack/boot and spark plug is NOT the problem but instead it could be a back fuel injector.....or a bad piston/valve, which is probably more likely considering you're running NOS without a tune.

If it does not spark after that what could cause the computer to not send a spark to that cylinder ??

Its not going to be a bad computer. Here are you ONLY options of what is wrong with that cylinder:

Spark plug
Coil
Boot
Fuel Injector
Piston/Valve damage (i.e. compression loss causing ECM to see a miss)


The O2 sensor or any other sensor will NOT cause one cylinder to miss.

Hope this helps.........

 

[BlackMark8]

Thanks J, and my uncle DOES know what he's talking about, he has a 7 second car. so he knows more than all of us, but not on the mark 8's - besides he told me this over the phone he never actually looked at the car. Im hoping for an injector. It only smokes on startup and when i get up on it, accelerating hard or pushing the gas pedal down. Like i said it makes no sound what so over, almost sound normal at some points besides the rattle and smoke. Im pulling the valve covers off and see if its not just a rockerarm which one of my family mechanics seems to think it is, wish me luck !!

 

[J]

Try my trick on testing the misfire. You can do it by unplugging the injectors too.

Sounds like it smokes at all times EXCEPT idling, if that is the case, you probably got a hole in the piston or something to that effect, basically a hard mechanical failure.

Good luck man!

 

[BlackMark8]

Turns out i wasnt using the right tester for compressoion and turns out number 8 isnt getting any. so, i guess the head is coming off next. and someone told me i have to take the motor out to take the head off, is this true ? thanks again

 

[maxmk8]

Turns out i wasnt using the right tester for compressoion and turns out number 8 isnt getting any. so, i guess the head is coming off next. and someone told me i have to take the motor out to take the head off, is this true ? thanks again

The heads on these cars are HUGE. This is probably right. Not only that but the timing chains have to come off and that requires a special tool. It makes a TON more sense to just get a new engine and drop it in.

 

[driller]

I forgot what started this thread. Hmmm...

well i cant say what is causing the light, but i can tell you this much, 30 bottle of 100 shot through a stock motor with 160k on it, sounds like you have much more to worry about now than just a blinking light. the rough running and smoke is obvious signs on internal damage.

 

[J]

Turns out i wasnt using the right tester for compressoion

I'm not sure any amount of internet diagnosis is going to help you my friend. I think you should pick up a used engine, spend a day swapping it out and call it done. If you want to waste (yes I said WASTE) your time trying to diagnose it, feel free, but its all a waste of time.

Calculate it out.....

Say you need a new piston. You can't just throw one in, you'll need a rebuild. So.....

Atleast $400 for a rebuild kit including one piston if you can find a kit that sells just one.
Atleast $1500 for machine work.
Atleast $200 for gaskets/tune-up stuff/fluids.
Plus whatever labor is involved if you can do it yourself.

Sooo.....for around $2k (if you're lucky) you will have a "new" engine. And this is AFTER you WASTE all your time diagnosing the problem.


The easy way.....

$600 for a used engine
$200 for fluids/gaskets/tune-up stuff
Plus labor for the swap if you do it yourself.

$800 bucks and you're on the road again.

I know this first hand, I did it TWICE on the same car, haha.

 

[BlackMark8]

yea, and that may be what i do next... but. I still want to run nitrous. So shouldnt i beef up the new engine first? just a little? to hold a little nitrous? - I dont want to have a 15 sec car again. So any suggestions?

 

[maxmk8]

yea, and that may be what i do next... but. I still want to run nitrous. So shouldnt i beef up the new engine first? just a little? to hold a little nitrous? - I dont want to have a 15 sec car again. So any suggestions?

Umm it doesn't look like you learned anything out of this....

This car is old will break while producing the power you want.... you're starting with something that makes 220hp at best to the wheels and running at least 300 through it...

If it is not the engine next time it will be your trans. Stock parts can NOT hold up these stresses for long. Sure some somehow managed to squeek by... but if I were you i'd just get something that can take the abuse or build up the stock parts to handle the stresses...

I think it is cheaper to just by something that is faster out of the box than to make your mark into a 13 second reliable cruiser... but if money is no object you should get a used Cobra engine (NA one) and swap it in.

 

[J]

ive been running a 100 wet shot for about 30 bottles now

Yes bone stock, No tune, no other mods.

I still want to run nitrous.

GET A FREAKEN TUNE! This will prevent most of your engine failure problems man. I believe we mentioned this all throughout the thread, and also in another thread.

The NOS people would know more on this, but it sounds like to me that your engine when lean when you were hitting the NOS yo and it detonated and blew your shiz up.

You can run NOS all day AND all night long with a vehicle that is tuned because it is tuned to SAFE parameters. The way you were running things is pretty much like playing the lottery, it was going to fail, it was just a matter of time.

Put a used engine in, slap the NOS back on, get a freaken tune, and go spank some Cccchevys.

 

[driller]

Put a used engine in, slap the NOS back on, get a freaken tune, and go spank some Cccchevys.

+1

A guy at work I know has built a drag car. He's on his second engine, 3rd transmission and I don't know how many rear ends.

It's a big block Chevy in a gutted Camaro with a blower and nitrous. I asked him once how much boost he was pushing and he answered he didn't know, he doesn't have a boost guage. I foolishly asked him what his A/F ratio was with the nitrous and... you guesses it, he had no clue.

Now I'm sure his car is fast when it runs but I don't think I'll ever get to see it run. LOL

It's ALL in the tune. You can push the stock internals on these modular motors wayyy past stock HP levels safely and reliably with knowledge.

 

[maxmk8]

Put a used engine in, slap the NOS back on, get a freaken tune, and go spank some Cccchevys.

And some Hondas... especially yellow ones

 

[bryantaylor]

GET A FREAKEN TUNE!

and some guages. AFR is a key one like driller stated. stock timing at WOT + a ton of N20 + lots of use + runing it lean = kaboom! and when you get it back together, get colder plugs and a bigger fuel pump ASAP!

 

[XLRVIII]

I think you should pick up a used engine, spend a day swapping it out and call it done. If you want to waste (yes I said WASTE) your time trying to diagnose it, feel free, but its all a waste of time.
.

definately a waste of time to diagnose and repair.
Pull it and replace it....you'll come out quicker and cheaper.

 

[XLRVIII]

GET A FREAKEN TUNE! This will prevent most of your engine failure problems man. I believe we mentioned this all throughout the thread, and also in another thread.

+ a bazillion!

the stock engine will easily withstand a 100 shot.
The stock fuel table has enough fuel programmed in to "cover a 100 shot".

BUT..if your fuel pump is original/old/weak, then your just gonna wound the next motor you put in there.. "Beefed up or not".

a good solid nitrous tune from an "experienced engine tuner" (READ NOT LMS) will carry you along way in keeping your motor alive.

Fuel pump first, tune second..then and ONLY then put the nitrous back on.

ALSO.. heeding the advice and warnings people are telling you will also carry you along way.

 

[XLRVIII]

The NOS people would know more on this, but it sounds like to me that your engine when lean when you were hitting the NOS yo and it detonated and blew your shiz up.
.

precisely..

Consider the cylinder that got wounded... the #8 the "last fuel injector in line" is #8.

Definately leaned it out, more than likely the stock/weak/old fuel pump just couldn't keep up.

The stock AF ratio at 5000 @ WOT is 10:1 so the PCM is trying to do it's job, but the fuel pump just isn't up to the task.

255LPH pump from www.50resto.com for right at 100.00 will help ALOT!